The present invention relates generally to a dispensing closure for a container for dispensing liquids such as beverages, or other flowable materials, and more particularly to a dispensing closure configured to facilitate convenient use by consumers by either suction on the closure or by squeezing of the associated container, while avoiding inadvertent leakage of the container contents such as attendant to normal handling of the container.
Dispensing closures have become increasingly popular with consumers for all manner of flowable materials, including beverages, condiments, and the like. In a typical construction for beverages, a dispensing closure includes a valve structure having a valve element which can be manually moved between opened and closed positions, with the closure permitting dispensing of the container contents either by suction or by container squeezing when in the open position. U.S. Pat. No. 5,975,369, hereby incorporated by reference, illustrates a dispensing closure which is typical of this type of construction.
While the above type of dispensing closure has met with widespread consumer acceptance, it will be appreciated that the use of the closure mandates manipulation and manual positioning of the valve structure between opened and closed positions. This can sometimes detract from convenient use of the closure, since sometimes it can be desirable to be able to dispense liquid either by the application of suction, or by squeezing of the container, without first manipulating the valve structure of the closure.
Efforts have been made to provide dispensing closures which avoid the need for manipulation, and which permit dispensing either by application of suction, or squeezing of the associated container. In such arrangements, it has been determined that the valve arrangement should open easily at suction pressures less than xe2x88x920.38 pounds per square inch (psi), which has been determined to be the upper limit of the comfort range for the suction applied to a closure by a typical consumer. The problem associated with current technology is that such closures work via a pressure differential created across the valve structure. However, the leakage threshold for such a closure and container package is limited to the level of suction that can be comfortably applied by the typical consumer (i.e., less than 0.38 psi). Under normal use relative to typical temperatures, package orientation, vibration, and transportation, internal container liquid pressures greater than 0.38 psi are typically encountered, and thus the package can leak liquid, and in fact, would be expected to leak liquid by virtue of the design.
Accordingly, it is desirable to provide a dispensing closure with a cost-effective valve system that creates different opening pressure thresholds when comparing the vacuum developed through suction, and the internal fluid pressure developed within the package. It is desirable to have the opening threshold developed due to internal liquid pressure be substantially greater than the opening threshold developed due to suction provided by the consumer. This will provide the desired convenient use by a consumer, permitting dispensing either by suction or by container squeezing, while avoiding undesirable leakage of the package under conditions typically encountered during use.
The present invention is directed to a dispensing closure assembly for a container which is specifically configured to facilitate convenient use by consumers. A valve structure of the closure assembly is actuated by a pressure differential created across the valve structure, which pressure differential can be created either via suction by the consumer, or by an increase in internal liquid pressure due to squeezing by the consumer. Notably, the closure assembly is configured such that internal liquid pressures typically created during ordinary handling and use of the container are insufficient to open the valve structure, thus avoiding undesirable leakage of the closure assembly.
In accordance with the illustrated embodiments, the present dispensing closure assembly for a container comprises an outer closure body including an upper tubular portion, and a lower skirt portion configured for attachment to an associated container. The assembly further includes a central support stem positioned within the tubular portion, and a flexible valve member positioned in the tubular portion.
One of the support stem and the tubular portion define an annular valve seat, with the flexible valve member extending from the other of the support stem and tubular portion so that it bears against the valve seat in a first, closed position of the flexible valve member. The flexible valve member is movable from the first, closed position to a second position, wherein at least a portion of the periphery of the valve member is spaced from the valve seat to permit flow through the tubular portion.
In accordance with the present invention, a liquid seal lip extends from the one of the support stem and the tubular portion which defines the valve seat. The liquid seal lip is configured for engagement with the flexible valve member intermediate: (1) the other of the support stem and tubular portion; and (2) the valve seat, to limit the surface area of the valve member against which the liquid pressure within the container acts.
In certain illustrated embodiments, the present dispensing closure assembly includes an outer closure body including an upper tubular portion, and a lower skirt configured for attachment to an associated container. A valve retainer comprising the central support stem is positioned within the tubular portion of the outer closure body, with a disc-shaped flexible valve member positioned on the support stem, and extending from the support stem outwardly to a peripheral valve seat defined by the tubular portion.
The valve member is movable from a first, closed position in which the valve member bears against the valve seat, to a second, opened position wherein at least a portion of the periphery of the valve member is spaced from the valve seat to prevent flow through the tubular portion.
In order to provide the desired operational characteristics for the present closure assembly, these embodiments of the assembly include a liquid seal lip extending inwardly of the valve seat for engagement with a lower surface of the flexible valve member intermediate the support stem and the valve seat. The liquid seal lip acts to limit the surface area of the valve member against which pressure within the container acts. Notably, the liquid seal lip is intended to provide a liquid seal only, and permits the interior surface of the valve member to always be minimally exposed to atmospheric pressure.
Depending upon the specific orientation of the valve retainer within the upper tubular portion of the outer closure body, the valve member can extend generally downwardly from the support stem to the valve seat in the closed position thereof, and the valve member may be generally conic. In some applications, the valve member will be generally flat (i.e., non-conic) or may extend generally upwardly to the valve seat.
In accordance with one illustrated embodiment, the valve retainer comprises a separate component positioned within the outer closure body, with the valve retainer comprising an outer tubular portion, and at least one radially oriented bridge element for joining the support stem to the outer tubular portion.
In the preferred embodiment, the outer closure body defines an air vent passage for venting air into the container during liquid flow outwardly through the upper tubular portion. When a vent passage is provided, the closure assembly preferably includes a vent seal member positioned beneath the upper tubular portion of the outer closure body for closing the air vent passage.
For many applications, it can be desirable to provide an outer protective cover for the region through which liquid is dispensed, and to this end, the closure assembly can include a dust cover joined to the outer closure body. The dust cover comprises a cover portion for movement between a closed position covering the upper tubular portion, and an open position exposing the upper tubular portion for dispensing. When the dust cover is formed separately from the outer closure body, the dust cover can include a mounting ring for snap fitment to the outer closure body, with the cover portion being hingedly joined to the mounting ring. In the preferred form, the cover portion includes at least one locking element for cooperating engagement with the upper tubular portion of the closure body to releasably retain the cover portion in the closed position thereof.
When the closure assembly includes an air vent passage for venting air into the container, it is preferred to provide the dust cover with a vent block element for closing the vent passage in the closed position of the cover portion of the dust cover.
In another illustrated embodiment of the present invention, the flexible valve member of the closure assembly is annular (i.e., ring-shaped), and defines a central opening at its periphery. The valve member extends inwardly from the tubular portion of the closure body to the valve seat, which is defined by the central support stem of the assembly. This embodiment provides a stream-like flow of liquid as it is dispensed from the container through the central opening defined by the flexible valve member.
Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.